import React, { Component } from 'react'
// 引入store
import store from '../../redux/store'

export default class Count extends Component {
  /* componentDidMount() {
    // 检测redux中状态的变化，只要变化，就调用render
    store.subscribe(() => {
      this.setState({})
    })
  } */

  // 加法
  increment = () => {
    const {value} = this.selectNumber
    store.dispatch({type: 'increment', data: value * 1})
  }

  // 减法
  decrement = () => {
    const {value} = this.selectNumber
    store.dispatch({type: 'decrement', data: value * 1})
  }

  // 奇数再加
  incrementIfOdd = () => {
    const {value} = this.selectNumber
    const count = store.getState()

    if(count %2 !== 0) {
      store.dispatch({type: 'increment', data: value * 1})
    }
  }

  // 异步加
  incrementAsync = () => {
    const {value} = this.selectNumber

    setTimeout(() => {
      store.dispatch({type: 'increment', data: value * 1})
    }, 500)
  }

  render() {
    return (
      <div>
        <h1>当前求和为：{store.getState()}</h1>
        <select ref={c => this.selectNumber = c}>
          <option value="1">1</option>
          <option value="2">2</option>
          <option value="3">3</option>
        </select>&nbsp;
        <button onClick={this.increment}>+</button>&nbsp;
        <button onClick={this.decrement}>-</button>&nbsp;
        <button onClick={this.incrementIfOdd}>当前求和为奇数再加</button>&nbsp;
        <button onClick={this.incrementAsync}>异步加</button>&nbsp;
      </div>
    )
  }
}
